I have been keeping Rainbows for over 20 years in straight tapwater and I
have only once had any problem with ulcers. The fish in question were Wonga
Ck. Trifasciata which I bought at an auction. These fish apparently came
from a dubious breeder whom I found out afterwards had Ulcer Disease
throughout his hatchery. These fish were housed with a selection of other
fishes but only the Wonga fish became infected. I subsequently destroyed ALL
the fish in the aquarium, chlorinated everything in the tank and thoughly
wash the gravel and reset the whole thing up again. I have not had the
problem every since and also do not buy fish from auctions or where I do not
know the source of the fish or breeder.
I have been regularly monitoring my tap water since 1990 and during that
time the water has never been higher than 110 ppm General Hardness. the
average is 90 ppm.
I still believe that unfavourable environmental conditions will cause the
problem. However, if the fish you receive have been bred and raise in
unsuitable conditions then they are probably predisposed to the problem and
only need a small hiccup to trigger the problem.
Again I say - know where your fish are coming from!!!!
Cheers,
Adrian T.
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Adrian R. Tappin
atappin at ecn.net.au
http://www.ecn.net.au/~atappin/home.htm
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